Platen roll



April 24, 1956 J. 'r. DAVIDSON PLATEN ROLL Filed May 15, 1952 INVENTOR. 20 JOH/V 7. DAV/DSO/V H 23 BY I ZORNEY United States Patent PLATEN ROLL John T. Davidson, Dayton, Ohio, assignor to The Standard Register Company, Dayton, Ohio, a corporation of Ohio Application May 13, 1952, Serial No. 287,548

12 Claims. (Cl. 197-145) This invention relates to platen roll assemblies, as used in writing or recording machines. In some classes of writing machines, particularly tabulators and the like, it is necessary or desirable occasionally to replace one platen roll with another. This may result from a change in the width of the record sheet, or from a change in the weight or texture of the record material or in the number of copies to be made, a change in either latter condition being preferably accompanied by a change in platen roll to secure one of proper surface hardness. A solid platen roll, or one integrally united with the platen shaft, is undesirable in such an installation because it cannot be removed without at the same time disassembling and removing other parts of the machine or platen carriage. Accordingly it has heretofore been proposed to construct the platen roll from a plurality of mating sector components held together in a-readily detachable manner which allows removal and replacement-of the platen roll independently of other parts of the machine.

While it has long performed its intended functions in a generally satisfactory manner, the sector type platen roll, as heretofore known, suffers some disadvantage in power operated machines wherein the platen roll moves at high speed and stops abruptly, and wherein the type is driven against the platen by hammer blows. Such hammer blows can result in localized impacts of considerable force, particularly in the case of gang printing, wherein a number of adjacent type elements are struck simultaneously. The platen roll may be jarred thereby creating vibration and consequent double or shadow printing, the platen sectors being interconnected only at their ends.

The instant invention has in view the obviating of the above noted disadvantage in sector type platen rolls.

The object of the invention is to simplify the construction as well as the means and mode of operation of platen rolls, whereby such rolls may not only be economically manufactured, but will be more eflicient and satisfactory in use, adaptable to a wide variety of applications, having relatively few parts and be unlikely to get out of repair.

More specifically, an object of the invention is to lock the sector components of the platen roll together over substantially the full length of the platen roll.

Another object of the invention is to provide a combination of locking devices in a sector type platen roll, onelocking'together the sectors at their ends and the other locking together the sectors over substantially the full length of the roll, intermediate the ends thereof.

Afurther object of the invention is to provide a reinforcement for the platen roll, presenting a solid continuous surface in underlying support of the scams or division lines in the roll.

, Still another object of the invention is to combine in a platenroll the rigid and resistant qualities of a solid roll and the independent removability of a sector type roll.

" A further object of the invention is to provide a platen ice roll of the character described, possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein described.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation, as hereinafter described'or illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawing, wherein is shown the preferred but obviously not necessarly the only form of embodiment of the invention,

Fig. l is a view in perspective of one end of a platen roll assembly, constructed in accordance with the illustrative embodiment of the invention;

Fig. 2 is a view in cross section through the platen shaft, showing a mounting head in end elevation;

Fig. 3 is a view in side elevation, partly broken away, of one of the mounting heads;

Fig. 4 is a view in longitudinal section of the platen roll proper, showing the reinforcing tube therein, partly broken away;

Fig. 5 is a view in end elevation of one sector of the platen roll assembly, in cooperative relation to the platen shaft;

Fig. 6 is a view in cross section, taken substantially along the line 6-6 of Fig. 4; and

Fig. 7 is a fragmentary view in horizontal longitudinal section, taken substantially along the line 7-7 of Fig. 6.

Like parts are indicated by similar characters of reference throughout the several views.

Referring to the drawings, a platen roll in accordance with the instant invention comprises a multi-part metal cylinder 10 overlaid by a non-metallic material 11. The cylinder 10 constitutes the platen core while the material 11 is exposed and constitutes the surface of the platen, the material 11 providing a somewhat yielding and resilient covering for sustaining the impact of the type bars or other printing members. The core member 10 is split by longitudinal lines which divide the core into a pair of sector components 12. The outer covering 11 is similarly divided into sectors 13 corresponding to and aligned with the sectors 12. The cover sectors 13 are united with the core sectors 12, as by being adhesively bonded thereto, each sub-assembly of a core sector 12 and a cover sector 13 being an integral unit in the platen roll.

In the assembled position of the platen roll, the two sector portions are placed with their longitudinal edges in mating or abutting relation. Such edges may be plain or, as seen in Fig. 6, they may be formed with flanges 14 adapted to overlap one another and so inhibit relat-ive shifting of the sector portions in a radial sense.

The interior of the core member 10 is formed with broad screw threads 15, undercut to achieve a dovetail formation. Further, at each end the core member 10 is formed with a wedge shaped groove 16 extending annularly around the circumference of the core member. Still further, at one or both ends thereof, the core member 10 has a longitudinal slot 17 opening through its inner surface, such slots being defined by cut-out portions in mating edges of the sector halves 12. The slot or slots 17 serve, as will be seen, as keyways in the coupling of the platen roll to a platen shaft.

Received within the core member 10, and constituting a part of the platen assembly, is a tube 18. The tube 18 is centrally disposed in the core member 10, in a longitudinal sense, and has external screw threads 19 complementary to the screw threads 15 and interlockingly engaged therewith. The tube 18 is not so long as the core member 10, its ends terminating just short of the slot or keyway'17. At diametrically opposed points, near its midportion, the tube 18 is formed with elongated openings 20. The tube 18 is, like the core member 10, of multi-part construction, being made up of opposing sector portions 21. The sectors 21 have their longitudinal edges in abutting relation to achieve a cylindricallformation.

There is an opening 20 in each sector 21 spaced approximately 90" from the side edges thereof. The tube sectors 21 are made to correspond to the core sectors 12 so that the longitudinal split or division lines thereof may be aligned with the corresponding lines of the core sectors 12. When the parts are so positioned, and in the absence of any other consideration, it will be understood that the platen roll assembly is separable into its sector components. Thus, a core sector 12 and its associated sectors 13 and 21 may be lifted away from the other sector 12 and its associated parts. If, however, the longitudinal division lines in the core member and the tube 18 are misaligned. in the manner illustrated in Fig. 6, the result is .positively to lock the core sectors 12 into assembled relation. That is, by reason of the interlocking screw threads 15 and 19, the core member 10 and tube 18 may be separated into component parts only when the respective division lines thereof are aligned, since only in this relative position of the parts do the forces required for separation of the core member and the forces required for separation of the tube coincide with one another. It further will be noted that in the assembled position of Fig. 6, there is presented to the division lines in the core member 10 a substantially continuous solid portion of the tube 18 thereby materially reinforcing the core member 10 along this line.

As installed, the platen roll assembly is a part of a more extensive combination including a platen shaft 22 (Fig. l), the opposite ends of which are adapted to be journaled in the carriage of a writing machine or like device. The shaft 22 extends through the tube 18 and carries a fixed transverse pin 23, the opposite ends of which extend into the opening 19 in the tube. As confined within the core member 10, therefore, the tube 18 is connected to shaft 22 for unison rotation with the shaft.

For supporting the core member 10, the shaft 22 carries a pair of spaced apart mounting heads 24. Such heads may, as in the present instance, be comprised in pin wheel units which further include feeding pins 25 adapted to engage marginal perforations in record forms or other strip material for positive advancement thereof. Each mounting head 24 is carried by the shaft 22 for relative longitudinal adjustment. The shaft 22 is formed with a longitudinal series of peripheral notches 26 while r the head 24 carries a pivotally mounted latch member 27. ln a manner which it is not necessary to fully considcr here, the latch member 27 is spring urged into engagement with the shaft 22 to be received in one of the notches 26 according to the desired longitudinal positioning of the head 24. With the latch 27 so positioned the mounting head 24 is prevented from moving longitudinally along the shaft 22. If the latch is rocked out of notch engaging position, the mounting head may be shifted in either direction along the shaft to a new se lected position of adjustment. There it is again locked by allowing the latch 27 to return to cooperative relation with the shaft 22, where it reengages in a registering notch 26. Each mounting head 24 is, moreover, locked to the shaft 22 for unison rotation with the shaft by a key 28 carried in a hub 29 of the mounting head and received in a longitudinal kcyway 31 in the shaft 22. As seen, the key 28 projects above the hub 29, being adapted to enter into the slot 17 in the core member 10.

The hub 29 is formed with spaced apart flanges 32 and 33 defining end bearing surfaces for the core member 10 of the platen roll assembly. The flange 32 is formed with an annular wedge shaped rib 34 complementary to the wedge shaped groove 16 in the end of the platen roll assembly and engagea'ble in such groove when the platen roll is slipped on to or over the flanges 32 and 33 4 to assemble the platen roll relative to the mounting head 24. As so engaged in the groove 16 the rib 34 holds the sector elements of the member 10 in an assembled position. The sectors are thus locked together at the ends of the platen roll.

The component elements of the platen roll assembly accordingly are locked together at their ends by one means and further are locked together substantially over the full length of the platen assembly by another and supplemental means, the latter being defined by the tube 18. Moreover, as previously noted, a positive backing or support is furnished the platen along the longitudinal lines separating the core member 10 into its sector components.

In assembling and installing the platen roll, the two halves of the core member 10 are held together by hand while the tube 18, the elements of which are similarly held together, is screwed into the core member, this action continuing until the tube is substantially centered in the core member in a longitudinal sense. Following this the tube and the core are relatively adjusted in a rotativc sense until the split longitudinal lines thereof are brought into registry wtih one another. The as sembly then may be pulled apart or separated, with each portion of the assembled tube being received in and locked to a corresponding portion of the core. One portion of the assembled tube and sector is then placed on the platen shaft 22 so that one portion of the pin 23 in the platen shaft enters the opening 20 in the tube 18 (see Fig. 5). The other portion of the assembled tube and sector is then applied to the platen shaft in opposed relation to the first half, with the other portion of the pin 23 received in the respective opening 20 in the tube portion. Holding the parts so assembled, the core member 10 is turned relatively to the tube 18 and shaft 22, which motion is made possible by the fact that the tube 18 is locked to the shaft 22 through the pin 23. Such relative adjustment of the core member will ordinarily be continued until the respective longitudinal division lines of the core and tube are substantially at right angles to one another, as indicated in Fig. 6. With the parts so positioned, as before seen, the platen sectors are locked together and the platen assumes a unitary character. To complete the installation of the platen assembly, the mounting heads 24 are advanced upon the ends of the shaft, or vice versa, so that the key 28 may be received in the keyway or slot 17 and so that the wedge shaped rib 34 may be received in the groove 16. When this adjustment has been completed, and the mounting heads 24 locked in adjusted position by release of the latches 27, the assembly of parts comprising the mounting heads 24 and platen assembly is locked to the shaft 22. Removal of and disassembly of the parts may be effected by carrying out the above steps in a reverse order, and without removing or disturbing any other parts of the writing machine.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its ad vantages. 1

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect.

Having thus described my invention, I claim:

1. A platen roll for a writing machine, including an outer cylindrical member having a screw threaded interior and separable into a plurality of sector elements along fixed division lines, and an inner cylindrical member having a screw threaded exterior and screwed into said outer cylinder, the screw threads of said members being interlocking and said inner cylinder being also separable into a plurality of sector elements along fixed division lines, relative rotary adjustment of said elements to a position aligning the respective division lines enabling corresponding sector elements to be separated from the platen roll as a unit.

2. A platen roll for a Writing machine, including an outer cylindrical member separable into a plurality of sector elements along fixed division lines, an inner cylindrical member in intimate contacting relation to said outer member and also separable into a plurality of sector elements along fixed division lines, said outer and inner cylindrical members being relatively adjustable in a rotary sense to align and misalign the respective division lines therein, and interengaging formations on said cylindrical members locking the separable sector elements thereof in assembled relation in the misaligned position of said division lines.

3. A platen roll for a Writing machine, including a plurality of arcuate sector elements having their side edges in mutually abutting separable relation to define a cylindrical platen assembly, a reinforcing tube received in said platen assembly in intimate contacting relation thereto, said tube being constructed of separable mutually abutting sector elements like said platen assembly, and interlocking screw threads on said tube and said platen assembly serving to align and misalign corresponding sector elements thereof whereby alternatively to lock the platen sectors together or to release them for separation with corresponding sectors of the tube.

4. A platen roll for a Writing machine, including inner and outer cylinder assemblies split along corresponding longitudinal lines to define separable component sector elements, and means defining an interlocking engagement between said cylinder assemblies, said assemblies being relatively adjustable in a rotative sense to align the corresponding split lines thereof to release the assemblies for separation into their component elements, and to misalign such split lines to lock the assemblies in assembled relation.

5. A platen roll for a Writing machine, including a plurality of arcuate sector elements having their side edges in mutually abutting separable relation to define a cylindrical platen assembly, a reinforcing tube received in said platen assembly and in intimate contacting relation thereto, and helical interengaging portions on said tube and on said platen assembly extending around the contacting peripheries and over substantially the entire length thereof locking said sector elements in an assembled relation.

6. A platen roll according to claim 5, characterized in that said inter-engaging portions are interlocking screw threads.

7. A platen assembly for a writing machine, including a rotatable platen shaft, mounting heads carried by said shaft, a platen cylinder assembly in surrounding relation to said shaft and supported at its ends on said mounting heads, said platen cylinder assembly comprising separable sector components, means for locking said sector components in assembled relation at said mounting heads, and other means locking said sector components in assembled relation over substantially the full length of the platen cylinder assembly.

8. A platen assembly according to claim 7, characterized in that said other means is a tube received in said cylinder assembly and interlockingly engaged therewith over the length of the tube.

9. A platen assembly for a writing machine, including a rotatable platen shaft, a platen cylinder assembly in surrounding radially spaced relation to said shaft and comprised of separable sector components, mounting heads carried by said shaft and supporting the opposite ends of said platen cylinder assembly, interengaging mean on said mounting heads and said cylinder assembly locking said sector components in assembled relation, and a reinforcing tube in said cylinder assembly terminating short of said mounting heads and interlockingly engaged over its full length with said cylinder assembly.

10. A platen assembly for a writing machine, including a platen cylinder split along longitudinal lines into a plurality of separable sector components, a platen shaft extending axially through said cylinder and radially spaced therefrom, mounting heads on said shaft supporting the ends of said platen cylinder, means for locking said sector components in assembled relation at said mounting heads, a reinforcing tube received in said platen cylinder and split along longitudinal lines to define separable sector components corresponding to the sector components of said cylinder, said tube and said cylinder being relatively adjustable in a rotative sense to align and misalign the corresponding split lines in said cylinder and tube, and interlocking screw threads between said cylinder and tube locking the sector elements of said cylinder against separation when the corresponding split lines of said tube and said cylinder are misaligned.

11. A platen assembly according to claim 10, characterized by a connection between said shaft and said tube holding said tube against rotation relative to said shaft.

12. A platen assembly according to claim 10, characterized by a connection between said platen cylinder and at least one of said mounting heads, holding said cylinder against rotation relative to said shaft, said last named connection being releasable to allow hand rotation of said platen cylinder relative to said tube for aligning and misaligning of said longitudinal split lines.

References Cited in the file of this patent UNITED STATES PATENTS 291,654 Van Name Jan. 8, 1884 996,970 Burnham July 4, 1911 2,067,211 Sherman et al Jan. 12, 1937 

